docs: def importable(obj):
      """Check if an object can be serialised as a qualified name. This is done
      by checking that a ``look_up(object_name(obj))`` gives back the same
      object.
  
      .. |importable| replace:: :py:func:`importable`"""
      try:
          return look_up(object_name(obj)) is obj
      except (AttributeError, TypeError, ImportError):
          return False